Polymeric implant and a process for obtaining a polymeric implant

Abstract

The polymeric implant is obtained from a renewable source, comprising a body formed by at least one biodegradable polymer selected from the group consisting of polyhydroxyalcanoates (PHAs) and copolymers thereof, said body incorporating, in its micro-structure, an active ingredient in a sufficient quantity to control at least one oestrus cycle of mammal animals. The invention further refers to a process for obtaining a polymeric implant comprising the steps of: mixing progesterone or progestogen, at least one polymer of the group of PHAs, one polymeric additive defined by poly(ε-caprolactone), and at least one dispersant additive and/or solvent, to obtain a colloidal solution; evaporating the solvent of the colloidal solution, and forming a paste with the components dispersed therein; drying the paste to remove the residual solvents and control the granulometry of the polymer composite; extruding the polymeric composite and moulding the latter in an implant body.

1 . Polymeric implant obtained from a renewable source, wherein it comprises a body formed by at least one biodegradable polymer selected from the group consisting of poly-3-hydroxybutirate (PHB), poly-(hydroxyburate-co-hydroxyvalerate) (PHBV), and mixtures of these polymers and copolymers, said body comprising, in its micro-structure;
 an active ingredient in a sufficient quantity to control at least one oestrus cycle of mammal animals;   at least one primary antioxidant of the sterically hindered phenol type;   at least one secondary antioxidant of the organic phosphate type;   one additive of thermodynamic and kinetic control of crystallization; and   at least one thermal stabilizer.   
     
     
         2 . Polymeric implant, as set forth in  claim 1 , wherein the implant body further comprises a polymeric additive defined by poly(ε-caprolactone) (PCL). 
     
     
         3 . Polymeric implant, as set forth in  claim 2 , wherein the implant body comprises from about 5% to 60% of poly (ε-caprolactone) (PCL). 
     
     
         4 . Polymeric implant, as set forth in  claim 3 , wherein the implant body presents a molecular weight from about 10,000 to 800,000 Da. 
     
     
         5 . Polymeric implant, as set forth in  claim 1 , wherein the implant body comprises PHB and about 5% to 40% of valerate. 
     
     
         6 . Polymeric implant, as set forth in  claim 5 , wherein the implant body presents a molecular weight from about 10,000 to 1,200,000 Da. 
     
     
         7 . Polymeric implant, as set forth in  claim 1 , wherein the implant body comprises from 0.02% to 0.5% in mass of the primary antioxidant and from 0.02% to 0.5% in mass of the secondary antioxidant. 
     
     
         8 . Polymeric implant, as set forth in  claim 1 , wherein the implant body comprises from 0.02% to 0.5% of at least one thermal stabilizer of the lactone type. 
     
     
         9 . Polymeric implant, as set forth in  claim 1 , wherein the implant body further comprises from 0.05% to 3% of at least one secondary co-stabilizer of the process auxiliary type, constitutive of any one of the additives—internal lubricant, external lubricant and flow modifiers. 
     
     
         10 . Polymeric implant, as set forth in  claim 1 , wherein it comprises from about 0% to 0.25% of the additive of thermodynamic and kinetic control of crystallization selected from nucleants of sorbitol or sodium benzoate types. 
     
     
         11 . Polymeric implant, as set forth in  claim 10 , wherein the implant body further comprises a polymeric additive defined by poly(ε-caprolactone) (PCL). 
     
     
         12 . Polymeric implant, as set forth in  claim 11 , wherein the implant body further comprises from about 5% to 60% of a polymeric additive defined by poly(ε-caprolactone) (PCL). 
     
     
         13 . Polymeric implant, as set forth in  claim 12 , wherein the implant body presents a molecular weight from about 10,000 to 800,000 Da. 
     
     
         14 . Polymeric implant, as set forth in  claim 1 , wherein the active ingredient is selected from progesterone and progestogens, in a concentration ranging from about 5% to 20% by weight of the implant body. 
     
     
         15 . Polymeric implant, as set forth in  claim 14 , wherein the progestogens are selected from the group consisting of medroxyprogesterone acetate, fluorogestone acetate, melengestrol acetate, 30 levonorgestrel, norgestomet and gestodene, employed in a concentration ranging from about 1 to 20% by weight of the implant body. 
     
     
         16 . Process for obtaining a polymeric implant, wherein it comprises the steps of:
 mixing, under controlled heating, one active ingredient selected from progesterone and progestogens; at least one polymer selected from the group of PHAs, one polymeric additive defined by poly(ε-caprolactone), and at least one dispersant additive e/or solvent, to obtain a colloidal solution;   submitting the colloidal solution to a pressing/filtrating operation, under heating, so as to promote evaporation of the solvent and formation of a paste with the components dispersed therein;   submitting the paste to a vacuum drying operation to remove the still existing residual solvents and control the granulometry of the polymeric composition;   submitting the polymeric composite to at least one extrusion operation; and   moulding the polymeric composite to form an implant body according to different ways of application, through a process of injection.   
     
     
         17 . Process, as set forth in  claim 16 , wherein the pressing/filtrating operation of the colloidal solution is carried out under temperatures of about 70″ to 90° C. 
     
     
         18 . Process, as set forth in  claim 16 , wherein the polymer is selected from the group consisting of poly-3-hydroxybutirate (PHB), poly-25 (hydroxyburate-co-hydroxyvalerate) (PHBV), mixtures of these polymers and copolymers. 
     
     
         19 . Process, as set forth in  claim 18 , wherein the polymer is poly-3-30 hydroxybutirate (PHB). 
     
     
         20 . Process, as set forth in  claim 18 , wherein it comprises PHB and about 5% to 40% of valerate. 
     
     
         21 . Process, as set forth in  claim 18  wherein the implant body further comprises from about 5% to 60% of the poly(ε-caprolactone) (PCL). 
     
     
         22 . Process, as set forth in  claim 16 , wherein the active ingredient is present in a concentration ranging from about 5% to 20% by weight of the implant body. 
     
     
         23 . Process, as set forth in  claim 16 , wherein the progestogens are selected from the group consisting of medroxyprogesterone, fluorogestone acetate, melengestrol acetate, levonorgestrel, norgestomet and gestodene, employed in a concentration ranging from about 1 to 20% by weight of the implant body. 
     
     
         24 . Polymeric implant, as set forth in  claim 2 , wherein the implant body comprises from about 40% to 50%, of poly (ε-caprolactone) (PCL). 
     
     
         25 . Polymeric implant, as set forth in  claim 3 , wherein the implant body presents a molecular weight from about 100,000 to 500,000. 
     
     
         26 . Polymeric implant, as set forth in  claim 11 , wherein the implant body further comprises from about 40% to 50%, of a polymeric additive defined by poly(ε-caprolactone) (PCL). 
     
     
         27 . Polymeric implant, as set forth in  claim 12 , wherein the implant body presents a molecular weight from about 100,000 to 500,000. 
     
     
         28 . Polymeric implant, as set forth in  claim 1 , wherein the active ingredient is selected from progesterone and progestogens, in a concentration ranging from about 8% to 10% by weight of the implant body. 
     
     
         29 . Process, as set forth in  claim 18  wherein the implant body further comprises from about 40% to 50% of the poly(ε-caprolactone) (PCL). 
     
     
         30 . Process, as set forth in  claim 16 , wherein the active ingredient is present in a concentration ranging from about 8% to 10% by weight of the implant body.